Basic research toward understanding the pathobiology of cystic fibrosis requires a continuing and dependable source of cells, affected and unaffected by the disease. Thus, the primary objective of the Core Cell Culture Facility is to acquire airway tissues and culture airway surface epithelial and tracheobronchial gland cells. A tissue procurement system has been established for obtaining normal and cystic fibrosis airway tissue. Once obtained, surface epithelial tissue is enzymatically digested and liberated cells are established in primary culture. Tracheobronchial gland cells are isolated as acini and expanded through a single passage. Surface epithelial and gland cell cultures are evaluated for differentiated properties using light microscopy, electron microscopy and measurements of short circuit current and transpithelial resistance. Cells showings satisfactory features are distributed to investigators. If surplus cells are available, these are frozen for use later. Additionally, established cell lines routinely used by investigators are maintained in the Core Cell Culture Facility. The final aim of the Cell Culture Core Facility is to continue efforts to improve cultures, particularly those derived from tracheobronchial gland cells and to develop cell culture model systems applicable to the studies proposed by SCOR investigators. With respect to improving in vitro cell differentiation, both soluble factors (growth factors, hormones, chemicals) added to culture medium and insoluble factors (extracellular matrix components, air interface culture) are tested for their effects on airway gland cell growth and differentiation. Culture conditions that allow full expression of ion transport and mucus secretory function are two of the goals of this aim. However, the highest priority will be given to determining the culture conditions that promote serous gland cell differentiation.